feat: replace Cloudinary with MinIO for all media storage

- Create server/services/minio.ts: S3-compatible service (same interface as
  cloudinaryService) using @aws-sdk/client-s3 and MINIO_ENDPOINT env var
- Replace all cloudinaryService imports with minioService across routes.ts,
  routes/reels.ts, routes/remotion.ts, services/media-purge.ts
- Replace Cloudinary logo URL pattern (res.cloudinary.com/...) with
  buildMinioUrl() helper throughout all server routes
- GET /api/cloudinary/config now returns a logoUrl field (full MinIO URL)
  so clients never need to build the URL themselves
- Update settings pages (desktop + mobile): labels changed to MinIO
  (Bucket Name, Access Key, Secret Key)
- Update image-editor.tsx: remove Cloudinary URL transformation, use logoUrl
- Update media-utils.ts: simplify getVideoThumbnailUrl (no URL transforms)
- Add MINIO_ENDPOINT and MINIO_PUBLIC_URL to docker-compose.yml + .env.example
- DB table reuse: cloudinary_config.cloud_name = bucket, api_key = access key,
  api_secret = secret key — no migration needed

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.env.example

@@ -24,6 +24,12 @@ ENCRYPTION_KEY=your-32-byte-hex-key-here
 # Obtenez votre clé sur https://openrouter.ai/
 OPENROUTER_API_KEY=your-openrouter-api-key-here
 
+# Configuration MinIO (stockage des médias, remplace Cloudinary)
+# MINIO_ENDPOINT = URL interne Docker (ex: http://minio:9000)
+# MINIO_PUBLIC_URL = URL publique pour accéder aux fichiers (ex: https://media.example.com)
+MINIO_ENDPOINT=http://minio:9000
+MINIO_PUBLIC_URL=https://media.example.com
+
 # Optionnel: Configuration Facebook API
 # FACEBOOK_APP_ID=
 # FACEBOOK_APP_SECRET=